Two solutions of non-volatile solutes A and B are prepared. The molar mass ratio, (M_(A))/(M_(B)) = 1/3. Both are prepared as 5% solutions by weight in water. Calculate the ratio of the freezing point depressions. ((DeltaT_(f))_(A))/((DeltaT_(f))_(B)) of the solutions. If the two solutions are mixed to prepared two new solutions S_(1) and S_(2), the mixing ratio being 2:3 and 3:2 by volume for S_(1) and S_(2) respectively what would be the ratio ((DeltaT_(f))_(S_(1)))/((DeltaT_(f))_(S_(2)))?

Two solutions of non-volatile solutes A and B are prepared. The molar

1.	Two solutions of non-volatile solutes A and B are prepared. The molar mass ratio, (M_(A))/(M_(B)) = 1/3. Both are prepared as 5% solutions by weight in water. Calculate the ratio of the freezing point depressions. ((DeltaT_(f))_(A))/((DeltaT_(f))_(B)) of the solutions. If the two solutions are mixed to prepared two new solutions S_(1) and S_(2), the mixing ratio being 2:3 and 3:2 by volume for S_(1) and S_(2) respectively what would be the ratio ((DeltaT_(f))_(S_(1)))/((DeltaT_(f))_(S_(2)))?
Answer» Solution :`(DeltaT_(1))A = K_(f) xx 5/(95M_(A)) xx 1000, (DeltaT_(f))_(B) = K_(f) xx 5/(95 M_(B)) xx 1000` `therefore ((DeltaT_(f))_(S_(1)))/((DeltaT_(f))_(S_(2))) = ("MOLALITY of" S_(1))/("molality of" S_(2)) = [2/M_(A) + 3/M_(B)]//[3/M_(A) + 2/M_(B)]` `=(2 +3M_(A)/M_(B))/(3+2M_(A)/M_(B)) = (2 + 3 xx 1/3)/(3 +2 xx 1/3) = 3/(3(2/3)) = 9/11`